Measurer for thickness of float polished liquid film

Abstract

A measurer of liquid film thickness of float polishing is characterized by that a optical lever structure is supported by a smooth rotary axle, the optical lever has a curved leg with transition arc at its one end floating on the surface of liquid film and a reflector at its another end, and the parallel optical tubes are used to observe the variation of pitch angle of optical lever. Its advantages are high efficiency and high polishing quality.

Description

technical field [0001] The invention belongs to a measuring device for polishing liquid film thickness in the technical field of optical cold processing. Background technique [0002] In optical cold processing, it is often encountered that some lenses require ultra-smooth surface processing. For example, in short-wavelength optics, the extreme ultraviolet lithography system used in the manufacture of VLSI requires the imaging quality of the optical system to be particularly clear. It is required that the surface roughness of the optical lens is ultra-smooth less than 1nm (RMS). [0003] Generally speaking, for optical cold processing of ultra-smooth surfaces, the usual grinding method of direct contact between the workpiece and the grinding disc cannot be used, but the polishing liquid is used to fill the gap space between the surface of the workpiece and the grinding disc, and the grinding disc and the processed The relative movement of the workpiece forms a liquid film i...

AI Technical Summary

Problems solved by technology

This method only knows that the thickness of the liquid film has been adjusted. In fact, there is no concept of quantity for the thickness of the liquid film. Every t

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